1. Field of the Invention
The present invention relates to detection devices, movable body apparatuses, pattern formation apparatuses and pattern formation methods, exposure apparatuses and exposure methods, and device manufacturing methods, and more particularly to a detection device that detects a surface state of a measurement member, a movable body apparatus that is equipped with the detection device, a pattern formation apparatus that is equipped with the movable body apparatus, a pattern formation method of forming a pattern on an object held by a movable body, and an exposure apparatus and an exposure method that expose the object with an energy beam, and a device manufacturing method that uses the pattern formation method described above.
2. Description of the Background Art
Conventionally, in a lithography process for manufacturing electron devices (microdevices) such as semiconductor devices (integrated circuits or the like) and liquid crystal display devices, exposure apparatuses such as a projection exposure apparatus based on a step-and-repeat method (a so-called stepper) and a projection exposure apparatus based on a step-and-scan method (a so-called scanning stepper (which is also called a scanner) are mainly used.
In these steppers, scanners or the like, in general, position measurement of a stage that holds a substrate to be exposed (e.g. a wafer) is performed using a laser interferometer having a high resolution. However, the length of an optical path of a beam of the laser interferometer is as long as around several hundreds mm or more. Further, due to finer patterns to cope with higher integration of semiconductor devices, position control performance with higher precision of the stage has been required. For such a reason, the short term fluctuation of measurement values of the laser interterometer caused by temperature fluctuations (air fluctuations) of the atmosphere on the beam path of the laser interferometer is becoming unignorable now.
Accordingly, recently the technology, in which a linear encoder whose measurement values have smaller short-term fluctuation due to temperature fluctuations (air fluctuations) than the laser interferometer is used, has been proposed (e.g. refer to the pamphlet of International Publication No. 2007/097379 and the corresponding U.S. Patent Application Publication No. 2008/0088843, and the like). In the case where such a linear encoder is used, if a foreign substance exists on a scale, there is the possibility that measurement error occurs or measurement cannot be performed due to the foreign substance.